The present invention relates to the art of deposited antacid tablets and in particular, to a non-chalky flavored solid antacid tablet which disintegrates in the mouth to a smooth creamy pleasant-tasting emulsion devoid of the grittiness normally associated with antacids and which affords maximum surface contact of particles of the antacid.
Antacids generally available are of the insoluble type which function by raising the pH of the stomach to a desired value, between 4 and 5, and maintaining this pH for some period.
Insoluble antacids depend on surface area (antacid particle size) for their efficiency. The smaller the particle size, the larger the surface area--thus more contact between acid to be neutralized and the antacid neutralizer. Very small solid antacid particle size can be attained by operations such as milling. However, a chewable tabletted product requires the user to mascerate the tabletted mass with his teeth, an operation which does not provide the small particle size and increased surface area originally achieved in the milled antacid powder.
Palatability and "mouth feel" are also extremely important factors in formulating antacids. Conventional metallic carbonate and hydroxide insoluble antacid materials usually have both an unpleasant mouth feel and an unpalatable taste due to chalkiness, grittiness, dryness and astringent properties of these materials. Accordingly, the practical value of these antacid materials is substantially diminished since patients finding them objectionable may fail to take them as prescribed.
In an effort to overcome the above problems, flavorings have been employed with antacids to either mask or override the unpleasant dryness and astringent properties and chalkiness associated therewith. Unfortunately, it has been found that the flavoring merely masks the unpleasant taste, but the chalkiness, grittiness, dryness and astringent properties still remain.
It has also been suggested to coat antacid tablets with a coating material which will not dissolve in the saliva so that it masks the disagreeable taste and mouth feel and will dissolve in the stomach. However, it has been found that most coatings suggested for such use dissolve in the intestines and not the stomach and thus provide the antacid at the wrong site. Moreover, although the coating may dissolve in the stomach, the rate of dissolution may not be fast enough to allow for sufficient neutralizing reaction time of the antacid with gastric acid before the antacid is removed from the stomach by gastric emptying. U.S. Pat. No. 3,843,778 to Diamond et al. discloses a technique for coating antacid particles with a water insoluble, inert, non-toxic hydrocarbon oil which is formulated into suspensions or tablets which are said to be substantially free of the impalatable "mouth feel" properties associated with antacids. Oil coating of antacid particles cannot be carried out by mere mixing, admixing, combining, triturating or the like of an oil with antacid particles. Consequently, Diamond shows the use of an electronegative agent, such as a surfactant selected from an alkyl aryl sulfonate, or an alkyl sulfate or sulfonate, or sulfonated amides or amines, or sulfated or sulfonated esters or ethers, or a dioctyl sulfosuccinate, or a hydrated aluminum silicate, such as bentonite or kaolin, is employed to aid in adhering the oil to the electropositively charged antacid particles. The oil coating of Diamond is a monomolecular layer in very small amounts, i.e., no greater than 1:50 ratio of oil to antacid.
U.S. Pat. No. 3,253,988 to Scott discloses an orally administrable antacid formed of oils or fats, that is esters of higher fat acids and a trihydric alcohol, in combination with antacids. The Scott antacid may be in the form of a waxy solid, an emulsion or suspension.